Internal-combustion engine



Aug. 9 1927. 1,638,290

E. R. BURTNETT ET AL INTERNAL COMBUSTION ENGINE Filed Oct. 8, 1924 'y wm@ /f/TTK Patented Aug. 9, 1927.

y/Uru'rlzn .STATES PATENT oFFICE.

EVERETT R. BURTNETT AND HOMEB A.. BRUNELL, 0F LOS ANGELES, CALIFORNIA, ASSIGNORS T0 THE AUTOMOTIVE VALVES CO., OF LOS ANGELES, CALIFORNIA, Al

VOLUNTARY TRUST.

INTERNAL-COMBUSTION ENGINE.

Application med October 8, 1924. Serial No. 742,891.

Our invention relates generally to internal combustion engines of the two stroke cycle type, and more particularly to an ene power unit having three cylinders, the head ends of two of which are connected by a common clearance space and function as combustion cylinders, and the third cylinder of the unit functioning as a pumping cylinder for forcing gaseous fuel charges into the connected combustion cylinders.

The principal object of our invention is to provide an engine of the character referred to with a sleeveand means for reciprocating the same, which sleeve is arranged within one of the combustion cylinders and functions to control the transfer of gaseous fuel charges-from the pumping cylinder into the chambers of the combustion cylinders.

A further object of our invention is to provide simple and efficient means for driving the sleeve from the crank shaft of the engine and at the same speed therewith, and to arrange said driving connections so that the sleeve is reciprocated in proper time relation to the movement of the pistons within the combustion chambers and the piston in the pumping cylinder.

With the foregoing and other objects in view, our invention consists in certain novel features of construction and arrangement of parts that will be hereinafter more fully described and claimed and illustrated in the accompanying drawings, in which Figure 1 is a transverse vertical section taken centrally through the three cylinders of an engine of our improved construction;

Figure 2 is a vertical section taken on the line 2 2 of Figure 1. A

Referring by numerals to the accompanying drawings which illustrate a practical embodiment of our invention, 10 designates a cylinder block in which is formed a gaseous lfuel pumping chamber 11 and a pair of combustion chambers 12 and 13, the axes of all of said chambers being parallel with each other, and said axes intersecting the axis of the crank shaft 14 of the engine. This crank shaft is j ournaled for rotation in suitable bearings 15 that are formed at the ends of a crank case 16, the latter being arranged beneath and connected to the cylinder block 10. The crank shaft 14 is provided With a crankv 17 that is disposed in line with the pumping chamber 11 and said crank shaft is also provided with a crank 18 that is disposed in line with the combustion chambers 12 and 13.' A piston 19 is arranged for reciprocatory movement with` in the pumping chamber 11, and said piston is connected to crank 17 by a connecting rod 20. Pistons 21 and 22 are arranged for reciprocatory movement respectively within combustion chambers 12 and 13, and said pistons are connectedv by suitable connecting rods, such as 23, to crank 18.

Secured tothe central portion of crank 18 and between the bearings thereon that receive the connecting rods 23 is a counterbalancing member 24 that is designed to counterbalance the weight of the connecting rods 23 and pistons 21 and 22 so as to minimize vibration of the crank shaft during engine operation. Formed through the wall of the pumping cylinder and at a point where they are fully uncovered andA opened only while pumping piston 19 is passing low or outer center are gaseous fuel inlet ports 25 that may be connected to av suitable source of gaseous .fuel supply, for instance,v a carburetor. Formed through the upper or in- Y ner portion of the Wall between chamber l1 and the pumping cylinder and the combustion chamber 12 is a gaseous fuel transfer port 26. These transfer ports communicate with an annular chamber 27 that surrounds the upper portion of combustion chamber 12, and leading from this annular chamber through the inner portion of the wall into said chamber 12 are ports 28.

Formed throughl the wall of the block that surrounds combustion chamber 13 is an exhaust port 29, the same being located so that it is uncovered and open only while piston 23 is passing low or outer center. Ar-

ranged for reciprocatory movement withinl the combustion chamber 12 and surrounding piston 21 therein is a sleeve 30 which, by its reciprocating movement, alternately covers and uncovers the inlet ports 28 that admit the gaseous fuel charge from the Vpumpring his cylinder to combustion chamber 12.

s eeve is reciprocated in any suitable manner in proper time relation to the movements of the pistons 19, 21 and 22, but we prefer to reciprocate said sleeve by the means illustrated in Figure 2, and which includes va 21 and 22 approach the lower ends of their leral extension or throat 36, the bottom of products of combustion wil link connection, such as-31, to a crank or cam travel piston 22 will uncover exhaust port on an eccentric shaft 32 that is driven di- 29 and immediately thereafter sleeve 30 will rectly from and at the same speed with have moved downward to a position where crank shaft 14. transfer inlet ports 28 are uncovered, therev Secured on top of the cylinder block 10 by admitting from pumping chamber 26 to is a head block 33 in the under side of the upper portion of chamber 12 a comwhich is formed a -pocket or recess 34 that pressed charge of -aseous fuel, it being uncoincides with 'and constitutes a clearance derstood that at t is time pumping piston space at the u per or inner end of pumping 19 is at the upper or inner end of its stroke. cylinder chamber 11. Formed in the under is the transfenports 28 arel thus opened side of the central portion of head block 33 slmultaneously wlth the opening yof the exis a shallow chamber 35' that constitutes a,n\ haust port 29 they inrush of gaseous fuel extension or clearance chamber for the head \into the upper portion of chamber 12 drives or inner end of combustion chamber 12, and before it through clearance chamber 35, leading from the side of this clearance throat 36 and chamber 29 the burnt gases chamber 35 to the immediately adjacent side and products of combustion resultant from of combustion chamber 13 is a shallow latthe previously ignited 1char e, and ,these be expelled which is inclined. The chamber-35 and latthrough exhaust port 29, thus leaving witheral extension 36 constitute a common clearin the piston clearance spaces in the upper ance space for the head or innerI ends of the portions of chambers 12 and 13 and in clearcombustion chambers 12 and 13, and seated ance space 35 and throat 36 a charge of in head 33 above combustion chamber 12 is fresh gaseous fuel and a relatively small an ignition device such as a spark plug 37, volume of residual products of combustion. the inner ends of the electrodes of which Sleeve 30 moves simultaneously with pistons project into .clearance chamber 35.

In the operation of our improved engine relatively short overall travel; consequently the various operating parts occupy the posion the first portion of the upward or comtions as illustrated in Figures l and 2 at the pression stroke of pistons 21 and 22 exhaust time a compressed charge of gaseous fuel port 29 will.be closed and simultaneousl is ignited in the common clearance s pace transfer inletports 28 will be closed by the above pistons 21 and 22, and the compressed sleeve,and on the succeeding upward travel charge is ignited as the result of a spark of pistons 21.and 22 the volume of gaseous produced between the terminals of the elecfuel and residual products of combustion trodes or plug 36. At this period `in the within the combustion 'chambers will be cycle of operations crank 17 has moved a compressed therein and within clearance suiiicient distance past low center to move chamber comprising the space 35 and throat pumping piston 19 into positionto nearly 36. During this compression stroke of the close the gaseous fuel inlet ports 25, it being combustion pistons, pumping piston 19 is understood that while said (pumping piston moving downward and on passing low center was passing low center sai inlet ports 25 it 'uncovers and opens inlet port 25 to admit were fully opened, thereby admitting to the to the pum ing chamber 11 a freshycharge umping chamber 11 a charge of gaseous of gaseous el. As pistons 21 and 22 ass ihel y f v high center, or an instant later, a s ar is The rise in pressure following combustion produced between the terminals of t e elecof the ignited gaseous fuel' charge in thev trode or plug 37, thereby igniting the comclearance space comprising chamber 35 and pressedY gaseous fuel charge and, as herein- 21 and 22, but at slower speed, owing to its l lll throat 36 will be directed against the heads before described, the pistons 21 and 22 will of pistons 21 and 22 to move the same downbe forced downward on their power stroke. wardly on their power stroke and as said Thus it will be seen thatwe have provided pistons thus move downward or outward a relativelysimple and practical power unit pumping piston 19 moves upward or inward, comprising a pair of connected combustion thereby comlressing the 'gaseous fuel charge cylinders and a pumping'cylinder and the within cham r 11 in the upper portion of transfer or inlet of gaseous fuel from the said chamber.. and within clearance space cylinder into the adjacent one of the com- 34. Simultaneously with the downward bustion cylinders being controlled by a movement of the pistons 21 and 22 sleeve sleeve that operates between the cylinder I 30 will be drawn downward through connecwall and the piston therein, said sleeve.l bev tions with the cam shaft that operates at ing connected so that it operates in proper crank shaft speed, but owing to the size and time relation to the movements of the isarrangement of the cam or crank to which tons within the combustion and pumping said sleeve is connected its movement will cylinders.

be relatively slow, as compared to the move" Obviously, minor changes in the size,`form ment of saidgpistons 21 and 22. As pistons vand construction of the various parts of our improved internal combustion engine may be made and substituted for those herein shown and described without departing from the spirit of our invention, the scope of which is defined in the appended claims.

IVe claim as our invention:

1. In a two stroke cycle internal coInbustion engine, a power unit comprising a pumping cylinder and a pair of combustion cylinders, the head ends of the latter being connected by a common clearance chamber, the pumping chamber being provided with a gaseous fuel inlet port, a gaseous fuel transfer port leading from the chamber in the pumping cylinder into the chamber of the adjacent combustion cylinder, the other combustion cylinder having an exhaust port, pistons arranged for operation within all of the cylinders, and a sleeve arranged for operation within the combustion cylinder having the gaseous fuel transfer ports for controlling the passage of gaseous fuel therethrough. 4

2. In a two stroke cycle internal combustion engine, apower unit comprising a pumping cylinder and a pair of combustion cylinders, the head ends of the latter being connected by a common clearance chamber, the pumping chamber being provided with a gaseous fuel inlet port, a gaseous fuel transfer port leading from the chamber in the pumping cylinder into the chamber of the adjacent combustion cylinder, the other combustion cylinder having an exhaust port, pistons arranged for operation within all of the cylinders, a sleeve arranged for oper- .ation Within the combustion cylinder having the gaseous fuel transfer ports for controling the passage of gaseous fuel therethrough, and means for reciprocating said sleeves so that the same is at the top center to close said transfer ports while the pistons within the combustion cylinders are at the upper or inner ends of their stroke.

3. In a two stroke cycle internal combustion engine, a power unit comprising a pumping cylinder and a pair of combustion cylinders, the head ends of the chambers within said combustion cylinders being connected by a common clearance space, one of the combustion cylinders being provided with an exhaust port, the other combustion cylinder being provided with gaseous fuel transfer ports that lead from the chamber within the pumping cylinder, and a sleeve ,arranged for operation within the combustion cylinder having the transfer ports for controlling the passage of gaseous fuel therethrough.

4. In a two stroke cycle internal combustion engine, a power unit comprising a pumping cylinder and a pair of combustion cylinders` the head ends of the chambers within said combustion cylinders being connected by a common clearance space, one ofthe combustion cylinders being provided with an exhaust port, the other combustion cylinder being provided with gaseous fuel transfer ports that lead from the chamber within the pumping cylinder, a sleeve arranged for operation wit-hin .the combustion cylinder having the transfer ports for controlling the passage of gaseous fuel therethrough, pistons arranged for operation within all of said cylinders, a crank shaft to which said pistons are connected, and

means for reciprocating said sleeve simultaneously with the pistons in said combustion cylinders.

In testimony whereof We affix our signatures.

EVERETT R. BURTNETT. HOMER A. BRUNELL. 

